Investigations
Investigations made as Proofs on Safety of the given Method |
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TO THE QUESTION OF OZONIZATION OF PHYSIOLOGICAL SALINE SOLUTIONS FOR MEDICAL USE S.D. Razumovski In the today medical practice the main methods of ozone therapy are based on the parenteral (mostly, intravenous) administration of therapeutic doses of ozone dissolved in physiological saline solutions or patient's blood. In Russia the most frequent method is parenteral (intravenous) drop-by-drop infusion (drip) of ozone dissolved in physiological saline solutions (mostly, 0,9% sodium chloride solution). There are medical ozone generators, which metrological systems allow to control ozone concentration both in ozone/oxygen gas mixture and watery solutions. There are studies about the kinetics of saturation and stability of ozone in physiological saline solutions. The aim of the present work is to investigate the possibility of formation of sodium hypochlorite in physiological sodium chloride solution due to oxidation of chlorine through ozone. According to the values of standard electrode potentials (table 1) the reaction of oxidation of chloride to hypochlorite through ozone is possible, but we have not found any publications containing any kinetic parameters of this reaction. Physiological sodium chloride solution was treated with ozone in special reactor where the solution was bubbled with ozone/oxygen gas mixture at ozone concentration of 60 mg/L and flow-rate of 1 L/min. For production of sodium chloride solution in two different series of experiments we used the following reagents - sodium chloride and sodium chloride type "extra" (common salt). Treatment time of sodium chloride watery solution with ozone, concentrations of reagents (table 2) were chosen according to the conditions actually used for production of physiological saline solution for ozone therapy i.e. being equal or exceeding (by 2-3 times) time and concentrations used for saturation of physiological saline with ozone. For determination of hypochlorite at presence of water-dissolved ozone the solutions were stored for several hours (not less than 12) in a dark cool (- 5o C) place until complete degradation of ozone. To flow ozone out of the solutions it is also possible to scavenge it by means of oxygen flow. The availability of hypochlorite in treated solutions was determined by means of standard iodometric method used for determination of active oxygen. As a result of the conducted experiments hypochlorite was not found in the treated sodium chloride solutions (table 2). Traces of active oxygen in the solutions of common salt are apparently related to concomitant micro-compounds of bromides and iodites that can be easily converted through ozone to bromates and iodates. Conclusions. Owing to dissolution of medical ozone in physiological saline solutions for medical use hypochlorite has been not formed. Table 1
Table 2
* * * RESULTS OF ANALYSIS OF POTENTIALLY POSSIBLE REACTION BETWEEN OZONE AND SODIUM CHLORIDE IN WATER G.A. Boyarinov, A.S. Gordetsov, I.N. Shamelashvili, N.V. Kulagina, S.V. Zimina, V.V. Sokolov, S.G. Kalyagina It is well known that ozone is a powerful oxidant. It oxidizes all metals with the exception of gold and metals of platinum group and reacts with most of other elements, causes degradation of halogenated hydrogens (except HF), converts the lowest oxides into the higher ones, reacts practically with all types of hydrocarbons and other organic compounds. In this connection N.M. Fedorovski doesn't exclude the possibility of formation of sodium hypochlorite, hypochlorous acid and heavy chlorates through ozonization of physiological sodium chloride solution. In the present work physiological saline solution (NaCl, 0,9%) was bubbled with ozone for 60 and 120 min in standard 200 ml bottles at temperature of 17-20o C through conveying ozone/oxygen gas mixtures produced by ozone generator "Ozon-N-100" through a special needle, ozone concentrations to be investigated and delivered at the outlet of ozone generator were: 10, 25, 35 and 100 mg/L. The ozonated solutions and physiological solution (control) were analyzed by means of spectrophotometers "Perkin-Elmer Spectrophotometer Coleman 575" (UV spectra) and "Specord IR M-80" (IR spectra). Previously the same devices were used for measurement of UV and IR spectra of fresh prepared reference sodium hypochlorite solutions (NaOCl). And the UV spectrum showed an intensive absorption stripe of maximum at 292 nm/ion OCl- (fig. 1). The UV spectrum of ozonated physiological sodium chloride solution showed a wide absorption stripe of ozone (200-300 nm) maximum at l=255 nm (Hartley stripe) (fig. 2, curve 2). The analysis of the curve and its comparison with the reference has pointed out that the UV spectra of samples of ozonated NaCl solutions do not contain absorption stripes of group OCl- (fig. 2, curve 2), and the curve character has shown that ozonization of physiological NaCl solution does not lead to formation of sodium hypochlorite even in the form of concomitant micro-compounds. In the IR spectrum ICl- stripe is not characteristic and has been not found in the reference sample. The investigation into the IR spectra of watery solutions of ozonated sodium chloride as well as IR spectra of their concentrates or dry residues has shown that they do not include even trace quantities of other chlorine-oxygen-containing ions that usually have intensive absorption stripes of maximum at 790 cm-1 (ClO2-), 980-930 cm-1 (ClO3-), 1140-1060 cm-1 (ClO4-). Thus, the above-mentioned data serve as convincing proofs that even long-lasting bubbling (up to 120 min) of physiological sodium chloride solutions (0,9%) with different ozone concentrations (up to 100 mg/L) does not lead to formation of chlorine-oxygen-containing ions. That allows us to recommend physiological sodium chloride solution for use as infusion medium parenterally administered to the patient as a carrier of ozone.
Fig. 1. UV spectrum of sodium hypochlorite |
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